You’re asking me to explain gender stereotypes to you and how those stereotypes influence what we’ll call “conventional wisdom” in a way that ultimately has no relationship to reality.

It’s like asking, “if women have always fought then why do people keep insisting there were no women warriors?”

Sexism, stereotypes, and even some cultural conventions have nothing to do with reality. To begin with the premise you started with, you’re already challenging stereotypes with the idea that women have any role in combat at all. Now, you’re asking “why aren’t women front line combatants while men are relegated to artillery?”

That’s hitting the ground running when everyone else is still up on the helicopter wondering if women can even make the jump. When most people are wondering whether it’s possible for women to fight at all, despite a large bevy of historic women who’ve bucked the trend. This is a subject on which PhD research papers are built, exploring social mores, conventions, gender roles, and stereotypes handed down to us century by century that insist women have no role in combat at all, that war and combat are “men’s work”, to be glorified for men by men and men alone.

So, why would the sword, which is a symbol of leadership, kingship, and heroes, be given to a woman?

We live in a culture that can barely acknowledge women have different body types, that their bodies are influenced and changed by the kind of exercise they engage in. We live in a culture that fights tooth and nail against taking female sports professionals seriously. We live in a culture where women being forced to register for the draft is up for debate, and large swaths would prefer they didn’t. We live in a culture where plenty of girls still see recreational martial arts as not for them, not because they don’t want to, but because they think they can’t do it.

Now, you’re here arguing for the fiction because that’s what’s been presented by the vast majority of media and culture as true.

Consider the number of female professionals and enthusiasts today, from the army to the police to the martial artists to the traditional fencers to the HEMA fencers. There has and always will be a strong interest by women in the combat arts. However, cultural perceptions and acceptability will also always be a factor. To ask the question you did is to both overlook the pervasive nature of sexism and disregard its normalization by buying into the idea that “if this is true then we’d see widespread evidence of it” without bothering to look. To overlook misinformation. To overlook gender bias. To ignore the fact that female contributions to history are, by and large, routinely ignored.

We live in a culture that can barely acknowledge women have different body types. We live in a culture where a vast number of women become disillusioned with working out because they were never taught muscle weighs more than fat. That weight gain is a natural first step to a work out because their bodies are building up muscle then the muscle will inevitably begin devouring the fat and they lose weight.

If one works out their upper body, consistently and constantly, whether male or female, they will develop those muscles. Drawing a bow works out the upper body as it relies on strength in the arms, shoulders, and chest muscles. This will lead to a much thicker upper body and strong shoulders, which is not necessarily an appealing mental image for someone buying into cultural stereotypes about feminine beauty.

There are very few female characters who accurately represent what a
women would look like after their training and often, in fiction, the
feminine ideal of physical beauty is what’s chased. Wish fulfillment
fantasies, generally, have little room for reality.

Assume instead that the person who is making the choice buys into the stereotypes. They’re looking for a kind of combat that is more safe, more feminine that active physical conflict. They may say they are about “female power”, but are buying into the idea that the bow is a safe, ranged weapon that requires less physical exertion/danger than a sword.

If you’re confused the stereotype is:

“Women are weak and therefore not suited to close combat. I know! I’ll give her a bow. Bows are ranged weapons, so she can kill at range, stay outside of combat without having to get her hands dirty.”

Never assume people argue from a position of knowledge, most of the time we work from a position of perception.

The sword also has the longstanding symbolic reputation as the weapon of the Chosen One in literature.

So, watch writers trip over themselves to make sure certain characters never get to lay their hands on one.